Owing to its ability to form dicarboxylic acids from alkanes, Candida tropicalis is a well-characterized ascomycete.
WO91/006660 describes Candida tropicalis cells that are completely inhibited in β-oxidation through interruption of the POX4 and/or POX5 genes, and achieve increased yields of α,ω-dicarboxylic acids.
WO00/020566 describes cytochrome P450 monooxygenases and NADPH cytochrome P450 oxidoreductases from Candida tropicalis and use thereof for influencing ω-hydroxylation, the first step in ω-oxidation.
WO03/089610 describes enzymes from Candida tropicalis which catalyse the second step of ω-oxidation, the conversion of a fatty alcohol to an aldehyde, and use thereof for improved production of dicarboxylic acids.
The cells and methods described so far are not suitable for the production of ω-hydroxycarboxylic acids or their esters, as the ω-hydroxycarboxylic acids are always only present as a short-lived intermediate and are immediately metabolized further.
ω-Hydroxycarboxylic acids and their esters are economically important compounds as precursors of polymers, and this forms the basis of the commercial usability of the present invention.
The task of the invention was to find a way of preparing ω-hydroxycarboxylic acids or ω-hydroxycarboxylic acid esters by fermentation in sufficient amounts, in particular in the medium surrounding the cells.